Voltage regulator



D. P. RUGER.

VOLTAGE 'REGULATOR. APPLICATION Flu-:0 APR. 21, 1920.

1,402,656. Patented Jan. 3, 1922.

2 SHEETS-SHEET l- D. P. RUGER.

VOLTAGE REGULATOR.

APPLICATION FILED APR. 21, 1920.

Patnted Jan. 3, 1922.

2 SHEETSSHEET 2.

DURL P. RUGER, OF CHICAGO, ILLINOIS, ASSIGNOR T0 CHICAGO, ILLINOIS.

THOMAS MARSHALL, or

VOLTAGE REGULATOR.

Application filed April 21, 1920. Serial No. 375,429.

To all whom it may concern:

Be it known that I, DURL P. RUGER, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in a Voltage Regulator; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.'

My invention relates to tors and rheostats for electric circuits, one of its general objects being that of providing a simple, inexpensive and dependable regulator for steadying the voltage of a circuit which varies in the potential supplied to the same. In this aspect, my invention aims to provide a self-contained regulator having a minimum number of moving parts and having all of its movable elements continuously housed, and having no electrical joints adapted to corrode or work loose; also, to provide such a regulator with simple means for preventing sudden jars from interfering with its operation.

In another aspect, my invention relates to rheostats in general, and aims to provide a simple and inexpensive construction involving a minimum of joints and connections the movable means for controlling the extent to which difierent portions of the resistance are included in a circuit. Viewed in this aspect, my invention also aims to provide a construction in which the contactvarying elements are freely exposed to afford the necessary radiation, and in which the entire rheostat forms a unit which can readily be attached to a controlling mechanism or detached from the latter.

In another aspect, my invention aims to provide simple, cheap and effective electroresponsive means for controlling the level of a liquid, and particularly for controlling the heightof a column of mercury; and for this purpose, aims to provide a simple solenoid arrangement and to provide means for checking the effect of surges or sudden jerky movements of the core of the solenoid, to utilize the high specific gravity of the mercury for'increasing the sensitiveness of the device, to prevent a loss or more permanent displacement of the mercury in case the de- Specificatio'n of Letters Patent.

voltage regulaand employing a conducting liquid as Patented 1 Jan.

vice is shifted from-itsnormal vertical posi-' tion, and to provide simple means for reducmg the friction of the core of the solenoid during its movements. 7 Still further and more detailed objects will appear from the following specification and from the accompany ng drawings, in which F g. 1 1 s a simplified and partly diagrammatic view showing the general arrangement of my invention.

Fig. 2 is a central and vertical section through a voltage regulator embodying my invention and suitable for use in the regulatlng of lighting circuits. I

1g. 3 is a horizontal section taken along the gorrespondingly numbered line of Fig. 4 is an enlarged fragmentary section through a portion of the resistance elements forming part of the device of Fig. 2.

Referring first to the diagrammatic view of Fig. 1, I accomplish the purposes of my invention by employing a column of mercury as the means for short-circuiting varying portions of a resistance consisting substantially of a strip zigzagged upon itself, and by controlling the height of this column of mercury through the action on the iron core of is to be regulated. To accomplish this control, I provide a substantially U-shaped tube comprising a horizontal portion 1 connecting a slender vertical shank 2 with a much larger shank larger vertical shank 3, which adapted to afford the requisite supply of is mercury. The slender shank 2 alines with of substantially horiperforations in a series zontal resistance elements 4 superposed on one another, WhlCll elements are consecutivcly connected to each other at their ends so as to afford a unitary zigzagged resist ance, and which elements are insulated from one another except at their said connected ends. Each of these elements exposes its metal as part of the wall portion of the said alined bores, so that mercury forced upward in the shank 20f the U-tube will contact with the exposed metal of the strips and will .therefore electrically connect a .varying number of these strip portions according to the height of the cury. Consequently, sistance is connected ductor 5 as shown in column of merif the zigzagged rein series with a cona solenoid fed by the current which Fig. 1, the mercury will short-circuit varying portions of this resistance according to the height to which it ascends within the bore portions forming the extension for the shank 2 of the U tube. 5 To move the mercury for this purpose, I

provide a plunger 6 within the larger diametered shank 3 of the U-tube and desirably provide mechanism which makes this plunger automatically responsive in position to the current which is to be controlled. This I preferably do by making the plunger 6 fast upon the core of a solenoid 7 which has its winding in series with the resistance. Owing to the high specific gravity of mercury as compared with iron, the core will be floated on the mercury, and by suitably weighting this core, I can so nearly balance the core against the action of gravity that it will require only a very slight variation in the magnetic efi'ect of the solenoid to change the position of the core. Then, since the diameter of the shank 3 of the U-tube is much greater than that of the shank opening through the resistance elements, every movement of the plunger will be greatly magnified in the extent to which it varies the height of the mercury in the other arm of the tube,-

and will correspondingly vary the extent to which the resistance is short-circuited. This change in theresistance will in turn efiect the current flowing through; the solenoid '7 and will therefore change the action of the latter on the iron core 6, so that any excessive movement of the core will immediately -be followed by. a partial returning of the same, until the point is reached at which the proper balance is struck. By properly pro= portioning the various parts, I can therefore obtain an entirely automatic regulating action in an exceedingly simple apparatus which has as its only moving parts the core of the solenoid and the supply of mercury.

To prevent sudden movements. of the core 6 from causing an undue surging of the mercury in the resistance-shunting part of the mechanism,I desirably provide the horizontal connecting portion 1 of the U-tube with a contraction 8 which will retard the freedom with which mercury moves from one shank of the tube to the other, thereby enabling my apparatus to be used with good results even where it is subject to jarring. l also desirably provide simple means for adjusting the solenoid vertically with respect the U-tube, thereby enabling me to adjust t e controlling action without employing any complicated parts or any changes in the electrical connections.

In practice, I also desirably employ certain features hereafterdescribed more in detail, although I do not wish to be limited to the disclosed features of construction and. arrangement, nor to the purposehere set forth, it being obvious that a great many 65 variations mlght be made without departing from the spirit of my invention or from the scope of the appended claims. For example, Fig. 2 shows a commercial embodiment including a solenoid coil 7 housing a tube 9 of non-magnetic material which acts as a guide for the core of the solenoid. This iron core 6 has a relatively slender extension 10, also made of iron and extending into a tube 11 of a correspondingly smaller bore, which latter tube is threaded upon the lower end of the tube 9 and corresponds to the shank 3 of Fig. 1. The tube 11 is connected through a horizontal bore 12 of quite small bore with a horizontal bore 1 in a block 13 which is one of the two blocks between which the resist ance elements 4: are clamped. These elements 4. are superposed on each other after the manner shown in Figs. 1 and 4:, and have vertical bores which aline with each other and with the vertical bore 21 leading to the saidhorizontal bore 1. The bottom block 13 is here shown as clamped to the tube 11 by screws 15 connecting this block 13 with a clamp 14, while the block 13 is connected to the upper clamping block 16 by bolts 17, which bolts can be tightened to insure the proper joints for the various bore portions which extend through the resistance elements.

in practice, these bore portions may consist partly of the exposed'material of the strips as shown in Fig. 5 and partly of insulating washers 18 interposed between the successive folds of the unitary resistance member. By loosening the bolts 15, the two clamping blocks 13 and 16 together with the resistance clampedbetween them can be raised or lowered with respect to the solenoid, so as to aid in making the desired adjustment. v

In practice, the specific gravity of mercury is so much greater than that of iron, that 1 considerable energy is required for moving the iron core downwardly. To reduce the required efiort, I desirably load the core with a suitable weight 19 of lead, and I also desirably hollow the upper portion of the iron core proper so as to reduce the magnetic pull. Likewise, I desirably provide a soft iron stirrup 2'5 longitudinally embracing'the solenoid and having its free ends directed towards the iron core, substantially after the manner of Fig. 2, so as to increase the edectiveness of the solenoid by providing asubstantially closed magnetic circuit.

To reduce the friction between the core and the tube portions within which it moves, ll desirably provide ample clearance between the exterior of the parts 6 and 10 and the tube portions respectively housing these portions of the plunger. By doing so, I not only avoid the possibility of having the core stick or bind in its movements, but also permit some of the particles of mercury to enter between the core and the bore portions of the tube to act as a lubricant. I also desirably provide the clamping block 16 with bore portions 27 corresponding to those in the lower clamping. block and opening into the tube 9. By so doing, I vent the top of the slender shank of the U tube and also afford a.;connection through which the mercury can readily flow in casethe apparatus is upset or laid upon its side. With this in mind,- I also desirably round the top. of the lead weight 19, so that any mercury which might have reached the upper end of the tube 9 when the apparatus was laid upon its side'or even inverted will readily flow down to its proper position when the apparatus is again in an erect position. Consequently, I can readily assemble the entire apparatus as above described before shipping or erectin the same, and no particular precautions wi 1 be required in the handling even though I employ a liquid as one of the essential elements. For-example, I am picturing such an entirely self-contained apparatus in Fig. 2 as detachably secured to a dashboard'24. e

- and cost than the I am therefore able to provide an entirely self-contained unit of far greater simplicity controlling devices commonly employed for regulating the voltage of the lighting circuits on automobiles or railroad cars, or for use with farm lighta ing outfits where the speeds ofthe engines vary considerably. ,By suitably designing the resistance, '1 can reduce the difference in voltage involved by-the shunting of one strip after another to such a small amount as to avoid sparking, and since all the operative parts of my apparatus are permanently inclosed, I avoid both corrosion and the enterin of dust or other impurities, and v hence am a le to provide an apparatus which will remain in hlghly eflicient working condition indefinitely without requiring attention of any ln'nd.

However, the essential constituents of my invention as above described could readily be separated'and used for purposes where they are not required in Such a combination, 1t being "obvious,

for example that the mercurially shunted resistance or rheostat proper could function equally well if the ing part/of the housing for a column of mercury; and means for varying the height of the said column to cause the latter to contact directly with varying numbers of the said folds.

3. In an appliance of the class described, a solenoid having a substantially vertical axis, and having a core extending below the winding of the solenoid,ja tube into which the said extension of the core projects, a pair of perforate clamp pieces secured to the tube, and a plurality of-resistance elements disposed between the cclamp pieces, the said elements having alined bores connected through a perforation in the lower clamp piece with the bore of the said tube.

4. In a rheostat, a resistance strip folded back and forth upon itself and having alined bores in its folds affording part of the housing for a column of mercury; and e lectro-responsive means for varying the height of th said column and thereby varying the extent to which the resistance strip is directly short-circuited by the mercury.

5. In a rheostat, a resistance strip folded backand forth upon itself and having alined bores in its consecutive folds affording part of one leg of a U-tube containing a supply of mercury, and a solenoid havin its core disposed in. the other leg of the U-tube.

6. In a rheostat, two thin layers of conducting material electrically connected to each other onl at one end, and means for making an electrical connection between said layers at a point other than the said end, the said means including an electrically conductive fluid. n

' 7. The combination of a rheostat, a column of mercury entirely inclosed within said rheostat, a chamber communicating with said column, an additional supply of mercury in said chamber, and means within the chamber controlled by the circuit in which the rheostat isinterposed 'for varying the he' ht of said column.

8. In a r eostat, a mercury chamber comprising'a hollow loop having a pair of vertical shanks connected to each other at both ends, a solenoid core extending into one of the shanks, and a plurality of resistance elements having integral contact portions forming wall parts of the other shank.

9. In a rheostat, a mercury chamber comprisin a hollow loop having a pair of vertical s ends, a solenoid core extending into one of the shanks, and a plurality of resistance elements having integral contact portions formin wall parts of the other shank, the core of the loop being contracted at both its upper and lower ends between the two shanks to retard the movementof mercury from one shank to the other.

anks connected to each other at both 7 I Y shank of the U-tube formed into a series of strips in close prox-,

imity to each other on their broader surfaces, all of said Smile being. insulated from each other throughout their length except that they are connected together into one f series at their ends, alined perforations in all of said strips,'-. -1'neans cooperating with the said perforations to afiord a tube, a column of mercury in said tube, and means for varying the amount of mercury in said tube.

Signed at 1920.

Chicago, Illinois, April 17 th;

Dunn r. auenn. 

